The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. Air flow into gasoline engines is regulated via a throttle. More specifically, the throttle adjusts throttle area, which increases or decreases air flow into the engine. As the throttle area increases, the air flow into the engine increases. A fuel control system adjusts the rate that fuel is injected to provide a desired air/fuel mixture to the cylinders. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the engine.
The engine outputs torque to a transmission. The transmission may transfer torque to one or more wheels to propel the vehicle. In some vehicles, the transmission includes a dual clutch transmission (DCT). A DCT includes two input clutches: each clutch is associated with a respective input shaft. An odd gearset is coupled to one of the two input shafts, and an even gearset is coupled to the other of the two input shafts. At a given time between gear shifts, one of the two clutches receives drive torque while the other of the two clutches does not. In this manner, drive torque is transferred to one of the two input shafts and gearsets at the given time.
Gear synchronizers move along a shaft of the DCT to mechanically couple an output gear of one of the gearsets to an output shaft. Gear actuators control the positions and engagement of the synchronizers. While torque is being transferred to one of the two input shafts, an oncoming gear ratio associated with the other of the two input shafts may be mechanically coupled to the output shaft in anticipation of a gear shift. The gear shift from the current gear ratio to the oncoming gear ratio may be accomplished in a relatively short period by engaging one clutch and disengaging the other clutch.